Dressing mechanism



1, o. CARLSEN 2,363,293

' DRESSING MECHANISM Original Filed Nov. 13 1939 s Sheets-Sheet 1 finnentor ZEO/VHRD 0. Cam. SEN

2 1944. L. o. CARLSEN DRESSING MECHANISM 3 Sheets-Sheet 2 Original Filed Nov. 13, 1939 R M. a o K m z 0 V. 0 m w W L Nov. 2l, '1944.

1.. o. C ARLSEN DRESSING MECHANISM Original File'd Nov. 15, 1939 3 Sheets-Sheet 3 INVENTOR BY LEa/VARD 0. CARL SEN ATTORNEY 31,,

. "wheelend ofa 'spiral bevel gear H chine of known construction and showing an end dressingfmechanism constructed according to Patented Nov. 21, 1-9 44 :J 2.363 29 7 n mssma MECHANISM Leonard 0. Carlsen, Rochester, N. Y., 'assignor to I GleasonWorks, Rochester, N.'Y., a corporation ofNew York Originalapplication November 13,1939, Serial No.

304,150.- Divided and thisapplication August, 11,1942, Serial No.454,4o5 v e v 3 Claims. 11. 125-11) f The present invention relates to dressing mech anisms and particularly to mechanisms for dressing the tip surfaces of wheels used in the grinding of gears. This application is'a division of the application of the present inventor and Ernest Wildhaber, Serial No;:304,150, filed November 13, 1939.--

- In the grinding of longitudinally curved tooth "tapered gears such as are used in automotive drives it is necessary to grind only thesidesof -the'teeth because only the'sides of the teeth of a pair of gears do the driving and automotive gears are made of sufiicientsize to readily carry any {load likely to be encountered inuse. Longitudinally curved tooth tapered gearshave nowbeen:

introduced into the aeroplane field, however, and different 'conditionsare met with there; Aero plane gears are heavily loaded to keep theirsize and therefore their weightata minimum, and if th'e J'unctures of the bottom with the sides of a tooth-"space are not smooth, cracks tend to form at such junctures-wh'en the gearsare under load, causing eventual failure of the gears. Hence, it has been foundnecessary to grind the bottoms *as well as the sides of the tooth spaces of aero-u 'pla'ne 'gears to providesmooth -bottom surfaces {and smooth junctures of thesides with the bottomsg and to insure that the ground bottom surfac'es blend with the ground side surfaces in smooth, uninterrupted curves. 'Moreover, for maximum strength, proper fillet radii must be.

bottoms of the tooth spaces.

One object of the inventionis to provide a "ground at the juncturesof the sides with the 1 dressing mechanis'm'havingmeans for dressing-a one embodiment of ed thereon; a I j Fig. 2 is a fragmentary transverse sectionalfview on an enlarged scale, through the end dressing mechanism and showing the position of the dresser in dressing the tip .of-a'wheel;

, Fig. 3 is a diagrammatic view showing the relaitionof; the dressing diamond to the wheel in the dressing of thetip surface of the wheel, the 'view being a cross-section takenin the plane of-oscillation of the dressing tool; I

; Fig. 4. is a corresponding diagrammatic sectional view takenin the plane of the axis of the -grindingwheel; H a Fig; 5 is an elevational view of the dressing round on'agrindingwheel atthe juncture of a 7 side and the tip surfaceof the wheel so that -a wheel may be provided which will be able to grind j'smoothsides and bottoms'in the tooth spaces of a gear without any sharp corners at' the junctures of the sides with the bottoms.

Still another object of the invention is to prowide a dressing mechanismior simultaneously dressing 'thetopfof a grinding wheel and the rounds atthe junctures of top-with opposite sides of the wheel by a single swinging movement of a single'dressing tool. 7

. Other objects of the invention will be apparent recital ofthe appended claims. I "In the drawings:

' hereinafter from the specification and from the mechanism and its support, the view being taken looking in the direction of the arrow 5 of Fig. 2.

.Fig. 6 is a sectional; view-throughthesupport takenon thelinet-B of Fig. 5; 20

[direction of the arrow L'of Fig; 2, partsv being 1 Fi 7 is an elevational view looking in the broken away; and J v v 4 v Fig. 8 is a fragmentary elevational view, show.- ing particularly the knurled knob for operating the; end dresser and the stopfor limiting its mo- In the end dressing mechanism of thepresent invention; the dressing tool is mounted on, a

h swinging arm and dressing is effected by oscillation of this arm. The swinging arm'is mounted upona support which is adjustable so that the I axis of swing of the dressing-tool may be inclined I to a plane containing theaxis of the grinding wheel to be dressed. When so positioned, the end dressing tool, it swings across the tip of the "grinding wheel, will move'in a circular'pathinclined .to the" plane ofthe'wheel'and dress an elliptical surface "on thewheel in the plane of the Fig. 1 is an'elevational' view, looking at the v grinding maaxis of the wheel. It has been found that such a surfacefprovid es a'sufllciently fiatjtip' surface "on the wheel "to grind flat bottoms in the tooth space's'of the gear and at {the same time forms rounds on the wheel where'the tip joins the side surfaces of the wheel so-th'at the wheel will grind sides on the tooth-spaces. which blend into the bottoms of the spaces. 'With the elliptical top surface, sharp corners at the junctures of the v top and the sidesof the wheel are avoided, thereby eliminating the possibility of formation of sharp corners in the tooth' spaces of a gear ground with the wheel. Moreoventhe rounds formed by the elliptical end surface of the wheel will produce fillet radii in the tooth bottoms that mm give the gear teeth maximum strength;

-At times it may be desirable to dress the tip the present invention mountof the wheel to an absolutely fiat surface instead of an elliptical surface and to provide rounds only at the juncture of this fiat tip with the sides of the wheel. Adjustable stops are provided on the dresser to so limit its movement and operation.

The dresser shown is intended to be manually operated. It is mounted in a support which is adjustable laterally of the wheel axis to accommodate wheels of di'fferent diameters, and angularly to controlethe angle between the axis of swing of the dressing tool and the plane of the wheel axis; thereby to control the radius of the elliptical surface dressed n the wheel.

wheel so it may be positioned at a convenient point not to interfere with the gear being ground.

Reference will now be had to the drawings for a more detailed description of the invention.

The grinding wheel, which is to be dressed, is denoted at W. It is a rotary annular wheel having a'ctive'sid'e surfaces 31 and 32 and a tip surface '33.

Themechanism for dressing the wheel maybe carried by a bracket 35 which may be mounted for.

angular adjustment about the axis of the wheel The side-dressing mechanism forms no part of l the invention claimed herein and for that reason will not be referred to further. The end or tip dressing 'mechanis'm-is constructed as will now be described.

Mounted on the bracket "-35 for angular adjustment thereon about the axis X of the grinding wheel is a plate 2ft (Fig-1). This plate is "secured to the bracket 35 by bolts (not shown) which engage the arcuate T-slot 211 which 'is formed'o'n the front face of the bracket 35.

Mounted on the plate 210 for rectilinear-adjustment thereon is slide 212. This slide is secured any positioni'oi its adjustment on the plat'e"2jl0b'y a T-bolt 213 whose head engages in an elongated T-slot 214 formed in theplat'e 210 (Figs. 1 and 5). A pointer'215 and a scale 216 are provided to enabIe'this adjustment to be made'acc'urately. t

Mounted in the slide 212 for rotatableand axial adjustment therein is a cylindrical bar 2211 (Figs.

[1, 5 and'6) Keyedto thisibar'by'means of a key 221 (Fig. "6) isanippl'e 222. A cap member 223 is threaded on the outside of this nipple and fixedly secured thereto by a set-screw 224. screw 's haf t'22'5 is rotatably mounted in a hole n the cap member 22min is held against axial movement relative to the eap member by the washer 225 and't'he'thimble 221which abut, re-

spectively, algainst opposite sides of the cap mem-,

ber 223 v nd which are pinned to the screw shaft 225. The screw s'hait threads into a nut'2'28 that isthreacled into a bore 229 of'thebar 220. A pm 230 which is secured I in the thimb-le 221 serves to rotate the screw-shaft. Whenthe shaft'is roto determine the position or the center of arc of swing of the dresser, radially In addition, the dresser support 1 has an angular adjustment about the axis 'of the F aresupported on swinging arms 11 and tated, the bar 220 is moved axially in the slide 212.

The bar 220 carries at its forward end a plate 235 (Figs. 2, 5 and 6). This plate has an opening to receive the bar and has a pressed fit on the bar. As already stated, the bar 220 is not only slid'ably adjustable in the slide 212 but is also rotatably adjustable thereon. For the purpose of making the rotatable adjustment accurately 'a collar 240 is secured to the plate 235 by screws This collar is provided with graduations which read against a pointer 242 that is securedto the slide 212. The rotatable 235. The screw shaft may ms U which, passes through an arcuate housing adjustment may be made manually. After the adjustment has been made the bar is clamped in any a djus-tedposition by the clamping blocks 231 andfita' (Fig. '5) which are rounded to engage the periphery cf the bar and which are manipulated by the screw 239.

Mounted on the plate 235 for rectilinear adjustment thereon is a housing 245 (Figs. 1, 2, and 5). The adjustment of this housing on the plate may be made by means or a screw shaft 246 which is journaled in the plate'an'd which threads into a nut (not shown) that is secured to the plate be rotated by means of a knurled knob 241. The housing 245 is secured "in any adjusted position on the plate 235 by a screw 249 (Fig.=2) which passes through an gated slot 250 (Fig. 5) that is provided in the plate 235 and which threads i-nto thehousing 245.

Journaled ,in

thereon. This angularadjustment permits of adjusting the diamondso that it extends at right angles or any other desired-angle to the tipsurface '33 to be dressed. The diamond holder may be secured-in any adjusted position by a bolt -256 slot 251 in the arm 253 and which threads into the diamond holder.

The angular adjustment of the plate 210 on the bracket (Fig. 1-) and the angular adjustment of the plate-235and bar 220 on the slide 212 (Fig. 5) permit -of .positioning the housing 245 (Fig. 2') so that the axis of the shaft 252 is inclined at any desired angle to the tip'surface 33 of the grinding wheel W to be dressed. The rectilinear adjustment of the "slide 212 on the plate 210 permits of adjusting the diamond 255 in accordance with the height of the wheel to be dressed. The rectilinear adjustment of the bar 220 in the slide 212 permits of this setting being made more precisely, as to compensate for wear 'of the wheel. The rectilinear adjustment of the 245 on the plate 235 permits of positioning the diamond so that the center of swing of the diamond will be midway the sides of the wheel. 1

1 When the-diamond 255 is positioned so that the-axis of the shaft 252 is inclined,'as shown'in Fig. 2, at otherthan a rightangle-toa planecontaining the axis of the grinding wheel, it will dress an elliptical curve on the tip of the wheel. In aplane of the diamond rotation the diamond will, of course, trace a circular are 260 (Fig.3) on the tip surface of the grinding wheel but in the axial plane of the grindingwheeL-as illustrated in Fig. 4, the path of movement of the diamond will be an ellipse as denoted in heavy l inesiat.26 0'.- The elliptical curveprovides a'substantially flatsurface on the top of "the grinding the housing 245 on spaced anti-. friction bearings 2'50 and 251 (Fig. 2) is a shaft wheel While providing rounds at the sides of the wheel which blend intothe side surfaces 3| and 32 of the wheel without any sharp corners. Thus the dressing mechanism of the present invention permits of dressingthe-grinding wheel so that suitable fillet curves are produced at the root lines 'of opposite sides of each tooth space of a-gear or pinion ground with the wheel while the bottoms of thetooth spaces'areground substantially fiat. At the same time no sharp corners willbe formed at the junctures of the bottoms with the sides of the teeth. Hence sources of possible cracks in the gear teeth will be eliminated.

A knurled knob 21I'is keyed to the shaft 252 to permit manual rotation of the shaft to effect the dressing of the tip of the grinding wheel as described.

Adjustable stops 265 and 266 that thread into lugs or cars 261 and 268, respectively, formed on opposite sides of the housing 245 serve to limit the swinging movement of the end dresser. These stops are adapted to be engaged, respectively, with opposite sides of a lug 210 (Figs. 2, '7, and 8) that is formed on the knurled knob 21l.

Mounted in the lug 210 is a spring pressed'detent 215 which is engageable in a recess216 formed in a collar 211 that is fastened in any suitable manner to the housing 245. A coil spring 219 serves to hold the detent 215 in engagement With'the notch or recess 216. 280 is secured to the 'detentto enable the operator to retract the .detent from engagement with the notch 216 and to allow him to rotate the detent when retracted. The knob 280 has four equiangularly spaced notches 282 formed onits periphery; A pin 283, which is secured in the lug 210, is adapted to be engaged selectivelyin one A knurled knob of these notches to hold the knob 280 and detent 215 in any one of the four diiferent'positions in which the detent may be engaged with the recess 216. In addition, the knob 280 may be pulled out and rotated to a position where its bottom face will ride on the tip of thepin 283 so as to hold the detent out of engagement with the recess 216.

When ,the detent 215 is retracted far enough so that the knob rides on the topof the pin 283, the shaft 252 may be'swung through the. full angle determined by the settings of the stops 265 and 266. When the pin 283 is engagedin one of the notches 282 of the knob 286 so that the detent is in the position shown in Fig. 7 then the shaft 252 can be rotated until the stop 265 strikes the lug 210, but it cannot be rotated in a clockwise direction from the position shown because the detent prevents such movement. On the counterclockwise movement the detent simply rides up out of the notch 216. By disengaging the detent from the notch 216 and rotating the knob 280 through an angle of 180 from the position shown in Fig. 7,-the detent can be positioned to prevent counterclockwise movement of the shaft from the position shown while permitting clockwise movement through the distance limited by the stop 266. When the detent is adjusted to a position at right angles to that shown in Fig. 7, it looks the shaft 252 against rotation in either direction. When the detent is held out of engagement with the notch 216, full swing of the diamonds across the end of the wheel to dress the tip of the wheel, and rounds at the junctures of the sides of the wheelwith the tip is allowed. When the detent is in the position shown in Fig. '1 or in a position at 180 to that shown in Fig. 7, only a limited swing of the diamond 255 is possible and such in a counterclockwise direction the detentisin a position at 90 from the position shown in Fig. 7, thenno swing of the diamond is possible but the'diamond maybe moved by the knob 241 to dress a plane tip surface on the wheel. This may be desirable for dressing wheels for automotive work; It will be seen,therefore, that the present invention 'provides a dressing mechanism capable of a wide range of work.

While the invention has been described in connection with a dressing mechanism for dressing an annular wheel, it will be understood that in principle the dressing mechanism of this invention may be employed in dressing other types of wheels also. It will further be understood that while the invention has been described in connec appended 'claims.

Having thus described my invention, what I claim is: v

1. In apparatus for dressing the tip surface of ,a rotary grinding wheel, a support, a'shaft oscillatably mounted in said support, an arm secured to said shaft, a dressing tool mounted on said arm, a block secured to said shaft, a pair of stops adjustably mountedin said support and adapted to engage, respectively, opposite sides .of the block to limit swinging movement of the shaft in opposite directions, auxiliary means carried by the block which is engageable with the support to limit swinging movement of the shaft in one direction, means for oscillating the shaft to effect circular arcuate movement of the dressing tool, and means for moving said support in a rectilinear direction to efiect straight line movement of the dressing tool.

2. In apparatus for dressing the tip surface of a rotary grinding wheel, asupport, a shaft oscillatably mounted in the support, an arm secured to the shaft, a dressing tool mounted on the arm, means for swinging the arm to effect circular arcuate movement of the dressing tool, means for efiecting rectilinear movement of the support to effect a straight line movement of the dressing tool, a block secured to the shaft, adjustable stops secured to the support and adapted to engage opposite sides of the block to limit movement of the shaft in opposite directions, a detent mounted in the block, a recess in the support with whichthe detent is engageable, a spring normally holding the detent in engaged position, said detent being beveled at its engaging end, and means for holding the detent in disengaged position.

3. In apparatus for dressing the tip surface of a rotary grinding wheel, a slide, a shaft oscillatably mounted in the slide, adjustable stops carried by one of said parts and a relatively ,fixed stop carried by the other of said parts and adapted to be engaged with one or other of the adjustable stops on swinging movement of the shaft to limit the angle through which the shaft may be swung,

a slsatsmt aarri s by me 9; said par an Mam; 1, be gnga ed it the other par sel ctively dif er t ms t ons sa sl et n n o e pQs tion at d essing ool moun ed on the a m in offset mla i n t9 the axis Qt he hai a supp rt on hic ths' slid? is r ctilinearl m vabl me n in? mov g the s af o efieet wing ng m ve- 11. am 9 h dressing t ol i a s mfla arc ate path an se a ate m ns for mov n t e slid m cilin a ly on the uppo t o ef e t. ec il near m vemen o the dressing too LEO ARD Q- 'A SEN- 

